Shoe-stiffening material



CHARLES E. SWETT, OF BOSTON, MASSACHUSETTS, ASSIGNOR 0F ONE-HALF T0 HARRY H. JBECKWITH, OF BROOKLINE, MASSACHUSETTS.

SHOE-STIFFENING- MATERIAL.

No Drawing.

To all whom it may concern:

Be it known that l, CHARLES E. S-wn'rr, a citizen of the United States, residing at Boston, in the county of Sufl'olk and State of Massachusetts, have invented new and useful Improvements in Shoe-stiffening Materials, of which the following is a specification.

This invention has relation to stiffened fibrous materials of the character of those employed for stifi'ening the toe or counter portions of foot wear.

In the production of foot wear, it is the custom in many factories to employ a blank of an appropriate shape, say, for use as a toe stiffener, which is stiffened by an agent adapted to be softened by the application of heat. This blank is assembled with the upper, and, after the latter has been placed on the last, the blank is heated and softened by heat, so that, when the upper is drawn smoothly and tightly about the last, the blank conforms to the shape of the last, and finally sets in its molded state. Such blanks are cut from a sheet of fibrous material impregnated or treated with pitchy, resinous, asphaltic or other gummy materials or hydrocarbon compounds which will soften at a comparatively low melting point, but which when cold impart to the sheet toughness and resiliency.- It has been proposed to surface-coat such sheets or the blanks cut therefrom with a material or compound of the character of the impregnating material or compound, the two materials or compounds amalgamating or coalescing at their oints of contact, and both softening to substantially the same extent on the application' of the same degree of heat.

The present invention has for its object to provide a fibrous stiffeningsheet or blank, which is so treated as to increase the strength, toughness and resiliency thereof. Accordingly the invention consists of a sheet or blank of fibrous material having a non-friable surface coating which will not materially soften upon the application of heat. but which is of such flexibility as to permit the blank to be bent without cracking or disintegrating. For this purpose, I employ a surfacelayer of animal glue, casein, celluloid or their equivalents, which will not amalgamate with the compounds with which the sheet orvblank is impregnated.

In the preparation of the sheet, the latter Application filed October 14, 1921. Serial No. 507,758..

is impregnated with Montan wax or other suitable resinous or hydrocarbon materials such as ordinarily employed while the latter are in a molten fluid state. When the sheet has been cooled and the primary stiffening material has set, the sheet may now be coated, or the blanks of an appropriate size and shape may be cut therefrom and coated individually.

Assuming that the sheet itself is to be coated, a layer of animal lue may be applied to one or both faces t ereof, followed, if desired, by the tanning of the glue with formalin or formaldehyde to render it water-insoluble; or a layer of casein size may be applied; or, if desired, a celluloid solution or a solution of any other suitable colloid may be applied. The coating is permitted to dry and set.

Preferably only one face of the sheet is thus surfaced so as to leave the primary impregnating compound exposed on the other face.

If blanks are first cut from the sheet and skived, they may be subsequently coated with the colloidal layer of nonfusing material, so that the latter coats the skived edges.

A shoe stiffener, formed as herein described. consists of a fibrous body of the desired shape impregnated with a stiffening compound which is softened and liquefied by moderate heat, and surfaced bya flexible coating united to or interlocked with the body, which does not soften or liquefy on the application of such heat, which adds strength and toughness to the blank, and which is sufliciently flexible to permit the blank to be molded to the desired form.

\Vhatl claim is 1. A shoe stiffener consisting of a fibrous body impre nated with a stiffening agent adapted to be softened or liquefied by the application of heat and to become stiff and resilient when set, and having a flexible surface coating of a heat-resistant stiffening material.

2. A shoe stiffener consisting of a fibrous body impregnated with a stiffening agent adapted to be softened or liquefied by the application of moderate heat and to become stiff and resilient when set, and having a flexible surface coating of a stiffening material which does not amalgamate with the said agent. and which is not liquefied or softened by the application of such heat.

liquefied by the application of heat and to become still and resllient when cold, coating the in'iprcgnated material with an additional stili'ening agent consisting of a colloidal material resistant to such heat; and cutting the fibrous material into blanks having skived edges.

In testimony whereof I have aflixed my signature.

CHARLES E. SWETT. 

